// position 定位样式
.p-a{
	position: absolute;
}
.p-f{
	position: fixed;
}
.p-r{
	position: relative;
}
.p-f-b{
	bottom: 0px;
	@extend .p-f;
}
.p-a-b{
	bottom: 0px;
	@extend .p-a;
}
.p-a-r{
	right: 0px;
	@extend .p-a;
}
.p-a-r-b{
	.right: 0px;
	@extend .p-a-b;
}
.p-f-t{
	top: 0px;
	@extend .p-f;
}
.p-f-t-l{
	left: 0px;
	@extend .p-f-t
}
.p-a-t{
	top: 0px;
	@extend .p-a;
}